1. Field of the Invention
The present invention relates generally to apparatus for two-sided cooking of food and, more particularly, to an improved upper cooking assembly which can be readily retrofitted to a conventional single-sided cooking grill.
2. Description of the Prior Art
The cooking of food in commercial or institutional establishments typically requires use of a grill. Grills in common use comprise a relatively large cooking surface, or platen, which is heated from beneath by electric heating elements or gas burners. Particularly in fast food establishments where hamburgers, or the like, are the predominant food item, two-sided cooking grills have proved to be quite useful. The two-sided, or clam shell, cooker includes an upper cooking apparatus which may be manually lowered onto or over a lower grill such that a heated platen in the upper cooking assembly contacts the upper surface of the item being cooked. Heat may thereby be applied to both surfaces of the item at the same time, thus offering the advantage of decreasing cooking time significantly. Two-sided cookers are particularly advantageous in the cooking of hamburgers, or the like, because the simultaneous cooking of both sides of the patty prevents undersirable curling or distortion of the patty due to uneven shrinkage, as occurs in a single-sided cooking process.
Two-sided cookers of conventional design are not without disadvantages. One shortcoming resides in the construction of the upper cooking assembly. In particular, it is common for the upper assembly to include a single platen which is formed with an internal heating element. In such an arrangement, the platen can be so heavy that it would excessively flatten or smash the item being cooked. Accordingly, prior art devices exist having adjustable spacer means for supporting the upper platen at a predetermined distance above the cooking surface of the lower grill. The spacer means may be made adjustable by various mechanisms, as taught by Harter, et al., U.S. Pat. No. 4,601,237 or Sabin, U.S. Pat. No. 4,729,296. However, these arrangements can be complex, adding to the cost of the apparatus, and the mechanisms can be difficult to maintain in clean condition when in use. Another disadvantage of the single upper platen devices is that food items tend to stick to the platen because of platen weight on the item. Various approaches exist for attempting to minimize the sticking problem. For example, Scanlon, U.S. Pat. No. 4,700,619 teaches a separate cooking plate which is removably attached to the upper platen and is coated with a layer of non-stick synthetic material. Also, Adamson, et al., U.S. Pat. No. Re. 32,994 discloses low-friction sheet means juxtaposed to the surface of the upper platen. While these arrangements address the sticking problem, in practice they are not convenient solutions. The low friction material of Scanlon wears away and must be renewed periodically, contributing to inconvenience and expense in the maintenance of the cooker. Moreover, the Adamson, et al, approach, as a practical matter, is also inconvenient and expensive.
Yet another disadvantage of conventional two-sided cookers is the hinge and counterbalance construction used to permit raising of the upper cooking assembly. Bergling, et al., U.S. Pat. No. 4,763,571, for example, teaches an arrangement involving counterbalance weights extending off the rear of the grill. Such a construction adds bulk to the grill making the grill undersirable for use in confined spaces. Other mechanisms comprising pulleys and linkages are costly to manufacture. None of the upper cooking assemblies now used in two-sided cookers lends itself to convenient retrofitting on a single-sided grill. Thus, a need exists for such a retrofitable assembly which is readily manufacturable and which overcomes the aforementioned disadvantages of current apparatus.